Businesses and governments have fought counterfeiters and data tampering with the use of hidden image technology. Hidden image technology (“hidden image technology”) is the process whereby one image is completely hidden (e.g., not readily perceptible to the naked eye) within another image through the use of various hidden image encoding techniques. Hidden (or secret) images can contain a variety of elements, such as textual, numeric, and/or even photographic data. Hidden images can be used for the purpose of adding a level of security and authenticity to items (e.g., images, documents) that bear the composite encoded image. Hidden image technology can be used in a variety of contexts, such as with payroll checks, shipping cartons, PDF financial documents, secure government documents (e.g., certificates of live birth, driver's licenses, etc.), pharmaceuticals packaging, and banknotes.
While some portions of a document or packaging can be readily counterfeited or altered, images protected with hidden image technology can resist tampering by relying on the use of specialized and controlled software to produce hidden images that may only be perceptible under appropriate circumstances (e.g., special lenses). When variable data such as a name, date, lot codes, or geographic destination codes get embedded as secret data into another image, the decoded secret data can be used to verify the authenticity of human-readable data rendered using ordinary means, and therefore confirm that the human-readable data was not counterfeited or otherwise altered. For instance, a malicious person may be able to readily alter the human-readable data but may not be able to readily alter the same data incorporated as a hidden image.
Methods of decoding a secret image hidden within another image have involved the use of a custom physical lens, such as a lenticular lens with a particular frequency. Different hidden image technology creators have used different lenses and decoding has been limited to specific physical lens is in the possession of the decoding person or system.